Brazing solder



Y Patented Jan. 3, i939 UNITED STATES PATENT" OFFICE BRAZING somna Franz R. Hensel and Earl I. Larsen, Indianapolis, Ind., assig'nors to P. R. Mallory & 00., Inc., Indianapolis, Ind., acorporation of Delaware No Drawing. Application September 16, 1937, Serial No. 164,187

1 Claim.

This invention relates to brazing solders, and

has for an object to provide an alloy for use as hardness of over 200. If suitably heat treated this 30 hardness can be increased to as much as 250 Brinell with an electrical conductivity of 30%. We have found that if the correct proportions of-elements are used an easy flowing and selffluxing gas welding rod can be obtained.

By using a flux consisting of, for instance, borax, boric acid, or similar substances, the flowing characteristics can be still further improved.

The composition which has given the best results, so far, was the following:

Percent Phosphorus 0.5 Nickel and/or cobalt silicide'"; 2 to Cadmium 4 1. Copper Balance The nickel silicide is of the formula NizSi and the cobalt silicide of the formula CoaSi.

Without heat treating a deposit made with a rod-of the'above composition will have a Brifiell v hardness of 120 to 150. If it is disired that the deposit should have a high heat and electrical ing operation from a temperature above 600 C. in connection with a subsequent bakingat a 5; temperature below 600? C. is to be applied.

While a preferred embodiment of the invenconductivity, and also a high hardness, a quench- The'ranges of alloying elements which we have found to be particularly suitable in connection with our new bronze welding red are the following:

Percent 5 Nickel and/or cobalt silicide 2t08 Cadmiumm -4; 0.05,to5 Phosphorus 0.05 'toi2 Copper Balance We have found that the combined addition of m cadmium and phosphorus is important because it will improve thefiowing and fluxing characteristics, and deposit a material which is completely dcoxidized, free of gases and blow holes. The bronze welding rods may also contain up'to several percent of one or more of the followingelemerits: zinc, tin, aluminum, manganese, iron or silver. V

In order to make the above composition suitable for electric arc welding, we propose to use it in conjunction with a coating which can be applied either by a dipping or extrusion process. The coating should containmaterial which will protect the metal during arc transfer and which will dissolve oxides formed during the welding process.

We have found that this rod is particularly suitable for building up worn surfaces .of flash welding dies, or resistance welding dies in gen-- eral. It can also'be used for'building up worn steel surfaces. In general, we recommend our new gas or arc welding electrode. for any purpose where a copper alloy is joined to another copper or ferrous alloy or a non-ferrous alloy.

As pointed out before, the deposit is free from blow holes, has a high tensile strength, can be treated so that it has a high electrical conductivity and it will also show a definite amount of elongation.

The heat treatment of the deposit may consi of annealing it for three (3) hours at 500 C. It is also possible to first quench the deposit from 850 C. and age-it afterwards.

We can vary the composition of our electrodes by changing, forinstance, the percentages of nickel and/or cobalt siliclde in such a manner that 'lower strengths and high elongation or higher strengths and lower elongation result.

, The change in composition will also eflect the improvement, which is of outstanding chemical What is claimed isl' and commercial value because it deposits direct- 4 Welding rods consisting of copper with cadly a hard and heat treated layer, while previously mium, nickel and/or cobalt silicide, and phosit was necessary to silver braze a piece of hard phorus in approximately the following propor-v 15 alloy to a. die. tions: 5

While the present invention, as to its objects Percent and advantages, has been described herein as Cadmium 0.05 to 5 carried out in specific embodiments thereof, it is Nickel and/or cobalt silicide; .1 to 10 not desired to be limited thereby but it is in- Phosphorus 0.05 to 2 l0 tended to cover the invention broadly within the FRANZ R. HENSEL. 10

spirit and scope of the appended claim. EARL I. LARSEN. 

